title: C-reactive protein and serum amyloid a overexpression in lung tissues of chronic obstructive pulmonary disease patients: a case-control study.
abstract: BACKGROUND
  Although researchers have consistently demonstrated systemic inflammation in chronic obstructive pulmonary disease (COPD), its origin is yet unknown. We aimed to compare the lung bronchial and parenchymal tissues as potential sources of major acute-phase reactants in COPD patients and resistant smokers.
  
  
  METHODS
  Consecutive patients undergoing elective surgery for suspected primary lung cancer were considered for the study. Patients were categorized as COPD or resistant smokers according to their spirometric results. Lung parenchyma and bronchus sections distant from the primary lesion were obtained. C-reactive protein (CRP) and serum amyloid A (SAA1, SAA2 and SAA4) gene expressions were evaluated by RT-PCR. Protein levels were evaluated in paraffin embedded lung tissues by immunohistochemistry and in serum samples by nephelometry.
  
  
  RESULTS
  Our study included 85 patients with COPD and 87 resistant smokers. In bronchial and parenchymal tissues, both CRP and SAA were overexpressed in COPD patients. In the bronchus, CRP, SAA1, SAA2, and SA4 gene expressions in COPD patients were 1.89-fold, 4.36-fold, 3.65-fold, and 3.9-fold the control values, respectively. In the parenchyma, CRP, SAA1, and SAA2 gene expressions were 2.41-, 1.97-, and 1.76-fold the control values, respectively. Immunohistochemistry showed an over-stained pattern of these markers on endovascular cells of COPD patients. There was no correlation with serum protein concentration.
  
  
  CONCLUSIONS
  These results indicate an overexpression of CRP and SAA in both bronchial and parenchymal tissue in COPD, which differs between both locations, indicating tissue/cell type specificity. The endothelial cells might play a role in the production of theses markers.
authors.affiliation: Unidad Medico-Quirurgica de Enfermedades Respiratorias. Hospital Universitario Virgen del Rocio, Seville, Spain. lcampos@separ.es
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: López-Campos
authors.forename: Carmen
authors.initials: C
authors.lastname: Calero
authors.forename: Belén
authors.initials: B
authors.lastname: Rojano
authors.forename: Marta
authors.initials: M
authors.lastname: López-Porras
authors.forename: Javier
authors.initials: J
authors.lastname: Sáenz-Coronilla
authors.forename: Ana I
authors.initials: AI
authors.lastname: Blanco
authors.forename: Verónica
authors.initials: V
authors.lastname: Sánchez-López
authors.forename: Daniela
authors.initials: D
authors.lastname: Tobar
authors.forename: Ana
authors.initials: A
authors.lastname: Montes-Worboys
authors.forename: Elena
authors.initials: E
authors.lastname: Arellano
mesh_terms: D000368:Aged; D001483:Base Sequence; D002097:C-Reactive Protein / Q000032:analysis*; D016022:Case-Control Studies; D017931:DNA Primers; D005260:Female; D006801:Humans; D008168:Lung / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000685:Serum Amyloid A Protein / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D000685:Serum Amyloid A Protein; D002097:C-Reactive Protein
keywords: C-reactive protein; COPD; Serum Amyloid A; gene expression; immunohistochemistry.